This invention relates to power supply couplers for battery chargers and, more particularly, to a power supply coupler suited for use with a battery charger for battery-powered electric vehicles.
It has been proposed to employ a non-contact, electromagnetic induction type battery charging device in an electric vehicle. The battery charging device usually includes a power supply charging paddle, which is connected with a cable to a stationary power supply device. The paddle is inserted into a power receiver coupler mounted in the electric vehicle to charge the vehicle battery.
The power supply coupler includes a case that forms a paddle-shaped plug, which is inserted into the power receiver coupler. The case forms a hollow interior space. A primary core is located in the hollow space, and a primary coil is located around the core within the hollow space.
The power receiver coupler also has a hollow case and forms a receptacle to receive the plug. The receptacle case encloses a secondary core and a secondary coil, which is located around the core.
When the power supply coupler is inserted into the power supply receiver, the core of the power supply coupler is aligned with the core of the power receiver coupler to form a magnetic path, and the primary coil is located in concentric relation with the secondary coil. If the primary coil is supplied with an electric power from the power supply device, an electric current is induced in the secondary coil. This inductive electric current is converted into a D.C. current, which charges into the battery of the electric vehicle.
The case of the power supply coupler is usually made of plastic to prevent electric leakage or electric shock. The case has an upper half and a lower half, which are mated. The coupler halves each have a thin-walled configuration including a cylindrical wall. The lower portion of the case is fitted into a hole defined by the corresponding cylindrical wall, and the lower portion of the primary coil is fixed to an outer surface of the cylindrical wall of the lower coupler half. Likewise, an upper portion of the core is fitted in a hole defined by the upper cylindrical wall, and the upper cylindrical wall in fitted a bore defined by the primary coil to form the power supply coupler. The two half are fixed to one another.
When handling the power supply coupler, the power supply coupler is frequently subjected strong impacts. For example, a person""s hand is apt to be erroneously removed from the power supply coupler during its insertion or removal from the power receiver coupler. When this happens, the plastic case of the power supply coupler tends to collide against a hard surface such as the ground and, which damages the power supply coupler. Since the plug portion of the power supply coupler has a rounded edge to facilitate insertion, the rounded edge is subjected to a large force per unit area when it collides against the ground surface. For this reason, the case is easily damaged.
It is therefore an object of the present invention to provide a highly reliable power supply coupler for a battery charger.
In order to meet the above and other objects, the present invention provides a power supply coupler for a battery charger. The power supply coupler includes a hollow case, a core accommodated in the hollow case, a coil located around the core in the case, and an interconnection member located between the coil and the case to transfer impact forces to the coil.
The present invention further provides a power supply coupler for a battery charger including a plastic case, one end of which has a paddle shape, a core, which is accommodated in the paddle-shaped portion of the case, a coil located around the core, and an interconnection member located between one part of the paddle-shaped portion of the case and the coil for transferring impact forces applied to an edge of the paddle-shaped portion to the coil.
Other aspects and advantages of the invention will become more apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.